This invention relates in general to the construction of couplers for vehicles and in particular to a new and useful coupler particularly for rail vehicles which includes means for absorbing excess impacts such as would occur in collisions.
A similar safety device is disclosed in German Pat. No. 1,530,223. In this device the magnitude of the absorbable shock is determined by the wall thickness and length of a hollow cylinder. Since the normal impacts to which the central buffer coupler is exposed are absorbed by a draw and buffer device provided in tandem therewith, the safety device may become effective under impacts exceeding a force of 2 million Newtons. Consequently, the safety device is relatively heavy, and, primarily it has a great overall length so that its use in practice is limited.
It is further known, from German Pat. No. 1,912,049, to provide a double-walled safety device, to be able to take up greater shocks with the same overall length of the device. Experience has shown, however, that with a frequent exposure to shocks at the limit of endurance, the excessive-shock absorbing capacity of the device lessens, since the device is located in the line of action of the forces. To ensure an effective protection of the travelers, especially in street cars and local transportation, the front walls of the vehicles are provided with anticlimb fenders intended to prevent the vehicles from wedging into one another under an excessive impact.